Morph Market appears to be the name that most people trust for online purchases.
It opens on the states by default so you'll need to change it to Europe (also covers S. Africa), but there's a huge variety of genes from very many enthusiasts on there.
I have never personally made a purchase from there (although I am watching a few), nor have I sold any on there, but I do have one listed to 'test the water' so to speak.
Also, nobody will judge you for purchasing your little boy from a pet shop, but you'll notice how your own preferences will change as time goes on and you gain more knowledge.
Despite the shop that didn't have the BP's welfare as priority having made the sale which some people would begrudge, you've also likely improved the animals quality of life by taking him from there.
It's a hard call for any BP enthusiast to make when they see one in poor conditions